Vehicles may be outfitted with a number of different powertrain assemblies, some of which represent a shift away from vehicles relying solely on internal combustion engines. This has led to developments such as electric vehicles and hybrids of electric and internal combustion engine driven vehicles which are gaining ground.
Hybrid Electric Vehicles, HEVs, are vehicles in which an internal combustion engine is combined with an electric propulsion system, e.g. an electric motor, in order to propel the vehicle. In many cases, the internal combustion engine will operate at fixed operating variables most suitable for the surrounding equipment such as a fixed revolutions per minute, RPM, and a non-varying fuel injection. For optimal fuel efficiency, both of the battery charge and the fuel of the internal combustion engine, the extent to which the internal combustion engine is used may differ in different driving scenarios. There is thus an interest in controlling the manner in which battery power being used or charged.
Several ways of controlling this exists, one of which is measuring the SoC levels of the battery pack, and instructing the internal combustion engine to charge the batteries when the SoC drops below a certain level. Another option is to allow the driver of the vehicle to decide when to turn on the internal combustion engine, or even set the SoC levels at which the internal combustion engine turns on. The internal combustion engine could also be turned on e.g. when the vehicle reaches high speeds, or when the driver requests a high amount of acceleration by pressing the accelerator substantially.
US20140018985A1 describes a powertrain of a Hybrid Electric Vehicle, HEV being controlled to determine how much battery power to be used by the powertrain. This is primarily based on instantaneous power requirements and a recharging rate of the battery to determine how much of the power produced by the powertrain is to originate from the engine and how much is to come from the battery. Further, a probability distribution over possible future paths of the vehicle is predicted and used to lower the energy expenditure of the vehicle, basing these possible future paths on past driver history. Further, a Bellman Equation is used as part of dynamic programming or a forward search algorithm to improve the energy expenditure.
While the powertrain according to US20140018985A1 might be useful in improving energy usage, there is still room for improvement.